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Specifications
Context window
1M—
API pricing
Input price
$2.00$1.25
Output price
$10.00$2.50
Cached input price
$0.20$0.20

These models have no shared benchmark scores.

Overview
CompanyAnthropicSpaceXAI
Release dateSep 28 2026Feb 17 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 and Grok 4.20 Beta don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok 4.20 Beta is cheaper on both input and output: $1.25 vs $2.00 per million input tokens, and $2.50 vs $10.00 per million output tokens. Figures are base-tier rates. Grok 4.20 Beta shipped 223 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude Sonnet 5.5 and Grok 4.20 Beta don't publish scores on any of the same benchmarks.